Quote:
Originally Posted by gary1101
What happens when these bolts are over torqued?Two concepts are important to understanding how a bolt works. They are Elastic Deformation and Yield Point. Elastic Deformation is metal's or, in this case, a bolt's ability to stretch and spring back to its original shape. Yield Point is where the bolt has been stretched past its elastic limit and can no longer spring back to its original shape. This stretching of a bolt and its pulling back creates Clamp Load. If, however, a bolt is over-torqued, and stretches past its Yield Point it can no longer maintain the Clamp Load.
So a loose wheel can be the result of an over torqued bolt. It happened to my moms car. A wheel vibration was the result of over torqued bolts. You could actually see that the bolts had stretched. Thank you Pep Boys for teaching my mom this lesson.
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agreed. however the regular mechanic only has the torque value to rely on..and that is a moving target. someone in the back office did the math and correlated a torque to a required tension load. for instance, i know a guy that puts on a lot of anti seize on his lugs..that throws torque values out the window since things got much slicker.